LECTURE Dynamics of calcium and its roles in the dendrite of the cerebellar Purkinje cell

Abstract. The calcium ion (Ca2B) serves as an important cellular messenger with spatio-temporally highly dynamic patterns. Not only Ca2B entering from the plasma membrane but also Ca2B released from intracellular store sites play crucial roles in neurons as well as in other cell types. The cerebellar Purkinje cell shows a variety of spatio-temporal Ca2B dynamics in its rich arborization, and the Ca2B release mechanism mediated by IP3 receptors and ryanodine receptors has been shown to be crucial for the induction of long-term depression, a form of synaptic plasticity, in this neuron. Purkinje cells in a model mouse line of human neurodegenerative disease, spinocerebellar ataxia type 1, showed ab-normal Ca2B release properties, which indicated tight regulation of Ca2B dynamics in the wild type Purkinje cell. Quantitative analysis of the complex Ca2B dynamics in the Purkinje cell dendrite is still in progress to elucidate the link between external stimuli and the resultant biochemical changes. (Keio